The Happy Addons for Elementor plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 3.21.0 via the `ha_condition_update` AJAX action. This is due to the `validate_reqeust()` method using `current_user_can('edit_posts', $template_id)` instead of `current_user_can('edit_post', $template_id)` — failing to perform object-level authorization. Additionally, the `ha_get_current_condition` AJAX action lacks a capability check. This makes it possible for authenticated attackers, with Contributor-level access and above, to modify the display conditions of any published `ha_library` template. Because the `cond_to_html()` renderer outputs condition values into HTML attributes without proper escaping (using string concatenation instead of `esc_attr()`), an attacker can inject event handler attributes (e.g., `onmouseover`) that execute JavaScript when an administrator views the Template Conditions panel, resulting in Stored Cross-Site Scripting.
